A theoretical framework for photon-subtraction with non-mode selective resources

TL;DR

This paper develops a theoretical framework for photon subtraction from multimode quantum light without mode selectivity, simplifying experimental setups and optimizing non-Gaussian state generation.

Contribution

It introduces a versatile theoretical model for non-mode selective photon subtraction, enabling easier experimental implementation and optimal state heralding in multimode quantum optics.

Findings

Framework enables non-Gaussian state generation with simple filtering

Optimizes conditions for heralding non-Gaussian states

Applied to Schrödinger kitten preparation from multimode squeezed states

Abstract

This work establishes a versatile theoretical framework that explicitly describes single-photon subtraction from multimode quantum light in the context of non-Gaussian state generation and manipulation. The treatment focuses on easy-to-implement configurations in which no mode-selective operation is available and evaluates features and advantages of scheme where only simple filtering stages are employed on the experiments. Such configuration, by considerably reducing the experimental overheads, makes experiments involving single photon subtraction easier to be implemented. Obtained theoretical framework allows retrieving, given a multimode input state, optimal conditions required to herald and then to detect non-Gaussian states, providing a practical and powerful toolbox for experiments' design. The application of the proposed approach to the case study of Schr\"odinger kitten preparation starting from a frequency multimode squeezed state illustrates the impact of the derived theoretical tools.